The present invention relates to methods of and apparatus for winding tire bead wire on a forming machine and, more specifically, to the forming of tire beads, particularly single wire beads, in a manner which securely attaches end portion of the bead wire to adjacent convolutions at the inner diameter of the bead.
In the construction of vehicle tires it is the usual practice to incorporate a stiffening bead at both the inside and outside openings where the tire is to be mounted upon a rim. One common method of forming tire beads is to grip the leading end of a metal wire and wind multiple turns of the wire in a groove on a drum and to cut the wire, forming a trailing end of the wire on the wound bead and a leading end to be gripped for winding the next bead. The wire is coated with rubber or a similar, synthetic covering and, during the winding process is maintained at a temperature sufficient to render the coating tacky, whereby adjacent wires in the bead adhere to one another.
The leading end of the wire is mechanically gripped at a position radially inwardly of the side-by-side turns which form the inner diameter of the bead. U.S. Pat. No. 5,603,799, issued Feb. 18, 1997, assigned to applicants' assignee and incorporated herein by reference, discloses an insert for use in bead-winding drums to provide a void or open space on the inner diameter of the wound bead for accepting the leading end of the wire after it is released by the gripping means. The inner terminal end of the wire is biased by the natural set or tendency of the wire to straighten itself upon release and thus enters and occupies the open space when the bead is removed from the drum. However, no physical force is applied to ensure that the end portion of the wire adheres to adjacent wires in the bead and there remains the possibility that it may become dislodged.
The principal object of the present invention is to provide a method of and apparatus for forming tire beads wherein the leading, initially gripped end of the bead wire is securely adhered to adjacent wires before removal of the finished bead from the forming drum.
A further object is to provide apparatus for applying a physical force to the inner, terminal end of a tire bead wire to urge it into firmly adhering relation to adjacent convolutions in the bead upon completion of the winding operation.
Another object is to provide a tool for pressing a wire end portion into a space on the inner diameter of a tire bead wherein the tool is reversible to effectively double its useful life.
Other objects will in part be obvious and will in part appear hereinafter.